Structure for controlling band width



July 26, 1960 R. J. cALLENDER 2,946,847

STRUCTURE RoR coNTRoLLrNG BAND WIDTH Filed April so. 195s g RRRRR a2 q RRRRN f F @45m FREQUENCY '\o k N s Q if L; s U R Y sani/idw INVENTOR RUSSEL d. CALLE/VDH? ATTORNEY United StatesPatent()y s'rnUc'rUru:` non CoNrRoLLrNG. BANniwInri Russen J. entender, 4117 University Ave., Y st. Paura, Minn Fired Api. so, 1956, senno. 581,595

lacunes. (c1. '11s-ss) rIhis invention relates toa method and structure 4for controlling band width in conjunctionwith v-afeontrolled slope at the picture carriers side and the sound carrier side of a resultant response curve of an LF. circuit of a one stage picture strip, or of a multiple -stage strip with each stage having the saine band width, and relates to phase correction of picture carriers side bands. More particularly, theainvention relates to prephased correction'of picture video' intelligenceand Sirnprovernentjin picture detail and resolution with an 'improved intercarrier sound take-off and improved rejection of sound interference -in the picture display, ywithcornplete climi# nation of all frequency band pass adjacent to the band pass filter tuning range by the combined properties of Va low impedance coaxial transmission line connecting, orr

inter-connecting, tuning coils as a band pass filter 4arrangement. The band pass -lter arrangement controls a one stage band pass, an output Aband'pass stagei or ya multiple band pass stage coupled `by the band pass larrangement and relatively controls the slope ofthe high and low frequency sides of the resultant response curve allowing the picturecarrier to be placed on the response curve near the base line of. the high frequency side of vthe response curve, allowing the picture carriers side bands to produce higher video amplitude fupon rectication of picture carriers side bands and kto extend to sound carrier limit with a sharp slope to fall to the sound carrier-s frequency.

In previous arrangement, the band pass control has been by the use of staggering L-F. ampliers to obtain large passage of frequency band width and vrelative independent turning of .each amplifier with the resultant stages to obtain va wide band pass and employment'of resistors lacross coils of amplifiers. Accordingly, it is an object of this invention to pro vide a method Aof utilizing a band pass arrangement for obtaining Ia controlled bandwidth .with `control of the degree of response curve slope at thepicture carrier .side of thefresponse curve. y y

` Another object of this invention is to provide `control of the degree o-fslope at the sound carrier side of -.a repicture ycarriers side bands and to control the amplitude of the sound carrier outputby controlling thecoupling vfactor of a coil'- arrangement in conjunction with control of amplitude of response curve output. v

-sponse cur-re,Y control [of` the frequency range of all l frequencybetween 4twolirnits forf relative control ofthe anni Patented July 25, '1960 f ice with'a vlow impedance transmis-sion line connected to a' tap `point von' each coil with an iron core inserted at the tap end to efect'a change of inductance at the ground endof coil to the tap, said inductance value controlling the band pass Width characteristics individually or together yand relatively controlling band .pass *amplitude by each increase in band width reducing lampditude off total ,band pass.

An. .additional ,objectof this invention is lto provide the -art with a method and structure for obtaining Wide lfrequency bandpass Width with 'an input resonant coil of the band-passv filterl arrangement establishing the high. frequency limit of the resultant response curve andthe output-resonant coil. the" low frequency limit of the resultantresponse curve v for aiect'ing band pass characterf istcs with a lotw .impedance transrnission'line connected to `a tap on each coil with the inductive magnitude across each .end ofthe transmission line establishing'minirnum frequency .band pass characteristics.

An` additional object of this invention is to provide the lart with a method and structure for obtaining slope tangle control `by magnetically vand electrostatically coupling .a high capacitive reactance resonant circuit to `the input resonant .tap coil ofthe band pass lter with the output tapcoilituned frequency 'to coincide withV the input coils frequency range in whichfthe energy is reflected from the high capacity resonant cireuitto the band pass ilters frequency 'range of a resultant response ,curve of two tap coils connected together by a low impedance transmission line. .Another object of this `invention is to give the art Aa method and structure Oef a band pass filter output stage to be connected directly to `a picture ltube without the use of avideo ampliiier and by using transistor stages of the band :pass lter arrangement `withcomplete elimination of Avacuum amplifiers.

Another object of this invention is to provide a method and structure for obtaining phase correction of Video yintelligence without ringing.

A` further vobject of this invention isl to rprovide Afor .improved sound output by correlating amplitude .of

sound carrier to picture carrier on the vresultant ,response cfu-rye with acircuit .which resonates near the frequency "range .of sound channel=.I.-'F. for the rejection of sound interference in picture display and amore `favorable-relAnother object ,of this invention 1s to provide la method of controllingand increasing the phase correct- Ving factor or Vcorrection ofthe phase shiftfactor or apre phase correction of picture carrier lside bands by a band pass viilterproviding controlled bandwidth characteristics -With relative control of the side bands ythereof*` An additional object voff this invention is to kprovide a method of producing a -prephasecorrection of the picturel carriers side bands through a band pass filter irng proving picture detail and picture resolution of the contrast range thereof.

to ,beat with4 the V,picture carrier to produce the vmc, intercarrier soundv output.

duction in amplitude of" sound LTP. carrier frequency required Further vobjects and advantages will V'heappanent from the'following,descriptionin conjunction with the Iaccompanying drawings, wherein:

Figure 1 is a schema c illustration of the structural arrangement embodied in this disclosure coupled with a grid Circuitf t Figure 2 a graph illustrating a resultant whole response curve land an image thereof obtained by the structural arrangement of Figure 1.

From the following discussion anddescription, it will i berecognized that anirnprovement in picture detail is vprovided-by control of the degree of slope and 'band in a single output stage for alpicture width and correction of phase shift to reproduce picture information with improved detail and resolution.

With reference to the arrangement shown in Figure l, the energy of the picture carrier and sound carrier is transferred from the plate .of a circuit, for example, The plate 10 is connected to the sound circuit side of a conventional receiver unit by conductor 11. The conductor 11 -is connected to ,conductor y12 which leads, on the one side, linto a resonant circuit represented by the variable capacitor 13, and an input coil 14, and on the other side to an intercarrier sound system through capacitor 16 and diode 17. As hereinafter illustrated, the diode 17 produces a 4.5 mc. sound beat note as the result of mixing I.F. sound carried and I.-F. picture carrier. The capacitor 13 is coupled across the iirst coil 14 and grounded through capacitor 18 connected at the low impedance end T2 of the coil 14. In this arrangement, the energy of the picture carrier at plate 10 is transferred as a tuned plate circuit to coil 14, to resonate at a 40 to 50 megacycle picture intermediate frequency, for example, under the control or action of capacitor 13 across coil 14 and core 19 inserted at the low impedance side of coil 14.

Inductively coupled and in facing relationship to the high impedance side T1 of coil 14 is the high impedance side T3 lof coil 20. The coils 14 and 20 are inductively coupled electromagnetically and electrostaticallv. Both coils 1'4 and 20 are wound in the same direction land coil 20 is coupled about one-eighth inch from coil 14, or close enough to coil 14 so that coil 20 starts to have theeifect of a brass slug on coil 14 and reduces the inductance at the high impedance end of coil 14. A tired capacitor 21 is coupled across the low impedance end T4 and the high impedance end Ta of tuning coil 20 and the low impedance side T4 of coil 20 and T2 of coil 14 are connected together bv conductor 22. The coil 14 in conjunction with coil 20 provides a tuned circuit to primarilv form and control the high frequency and picture carrier side, or degree of slope angle of the resultant response curve. The coil 14, in coniunction with coil 20. in a limited Way reduced the width of the band pass, or the characteristic width of the resultant response curve, in the manner as hereinafter will be apparent. That is, when center frequency is higher, as controlled by coil 20, and is tuned by core 25 toward the frequency range of coil 14, the band pass range of the response curve will increase the correcting factor of video intelligence in the picture carrier side band, in a limited way, and limits side band ringing. Such tuning also results in a controlled steeper slope at the high frequency side of the response curve, or on the picture carriers side, as is hereinafter illustrated and when output coil 30 circuit frequency is tuned to input coil 14 circuit frequency range, phase shift factor is corrected in resultant video intelligence. Thus, the resonant coil 20 with relative high capacity condenser 21, in relationship with coil 14 and coil 36" controls the energy of the response curve between the high frequency end of the curve and the low frequency end of the curve to increase the picture brightness and detail with simultaneous prephasing of the video information through regulation of the picture carrier side bands.

In reference to coil 14. capacitor 13, or on coil 14 at about a turn and one-half to two turns 'from the low impedance end T2 of coil 14, isa transmission line tap 26 connected. through blocking capacitor 27, to a non-reactive transmission line 28. The transmission line .28 is one in which no reflections of energy are apparent or the same capacitive or inductive reactance is present at each end. The energy of the picture carrier side bands is transferred through line 28 and transmission line tap 29 to coil 30 at point T about a turn and one-half to two turns from the low impedance end T2 of coil 3i). The

' blocking capacitor 27 serves to isolate B plus and the transmission line 28 may be of any desired length. This serves to space the input coil 14 and output coil 30 in electromagnetically.

completely isolated relationship electrostatically and The casing 31 on line 28 is grounded at the ends as at 32.

The opposite end of the transmission line 23 is connected by the line tap 29 to the coil 30 at about a turn and one-half to two turns from the low impedance end of the coil 30. This transmission line 28 is the only means of connecting and converting energy from coil 14 to coil 3i).V The band -pass factor of the coils 14, 20', and 30` and line 28 is of a high frequency characteristic or arrangementV with reference to circuit losses. The coil 30 has connected across its Vlow impedance side, which is grounded at T2, to its high impedance side T1, a variable capacitor 33. The variable capacitor 33 andY coil 30 are primarily tuned to coincide in frequency range of coil 14 and capacitor 13 for high degree phase correction and relatively tunes all the picture carriers side bands. Co-jointly, the coil 14 and capacitor 13, in conjunction with coil 20 and capacitor 2.1, and coil 30 and capacitor 33 relatively tunes all side bands of the picture carrier.

A coupling capacitor 36 connects the high impedance 'side T1 of coil 30 with the video rectifier 37 and output and the load resistor 38 vwhere the resultant response curve is measured.

While coil 30 is relatively electrically the same as coil 14, it is preferable to electrostatically shield the same at the high impedance end T1 by a small coil 45. The small coil 45 is similarly wound in slightly spaced relationship, for example, oneeighth inch, to the high impedance end T1 of coil 30 and is grounded on the low impedance end T5.

Iron cores 19 and 46 are inserted in the low impedance ends T2 of coils 14 and 30 respectively. That is, the iron core 19 is adapted to be adjustably mounted within the low impedance end of coil 14. The iron core 19 aids in tuning the plate circuit in coil 14 and increases the inductance at the low impedance end T2 of the4 coil 14. The iron core 46 similarly assists in tuning the coil 30 and each of the cores increases the inductance at the low impedance ends of their respective coils at T, or line taps 26 and 29 on coils 14 and 30, respectively. Thereby, the cores 19 and 46 change the inductance of coils 14 and 30, respectively, from points T to T2 more than at any other part of the coils. This increase in inductance has the property of being equivalent to moving the line taps 26 and 29, or from T, to nearer the middle of the coil and increases and controls the width of the band pass or widens the frequency range of the filter, and provides a band width of frequencies which are substantially flat and of equal amplitude. As indicated, the cores 19 and 46 are adjustable to provide for proper band width. Any movement of the cores 19 and'46 will relatively increase or decrease the relative frequency range of the coils 14 and 3i); respectively, but'this shift of frequency move- 'ment can be corrected by capacitor 13 of coil V14 and It is believed that the -relative operation of the band pass lter in prephasing the video information by controlling -the energy in the response curve between the high frequency end of the curve and the low frequency end lof the curve, with respect to relatively regulating the picture carrier side bands, will be more clearly understood from the following description relative to the response curve graph shown in Figure 2. As indicated, the phase correction property for obtaining clearer video intelligence relates to controlled band Width characteristics with controlled slope, as illustrated at the picture carrier side 48 of the response curve A. IIn the present structural arrangement, as described, "a pre-phase correction of the video information is produced when the relative tuning properties of the connected coils of the band pass filter 'arrangement .are properly adjusted to 'affect band width characteristics and tune both 'sides of the response lcurve A. j

The coil 14, with coil 20, isartunedcircuitwhich affects the low frequency side bands/of 'carrier slope 48 of the response curve A and Awhen properly tuned with coil 3l), relatively controls Athehigh frequency 'side :bands of response curve side 49. That. is, when Lthe Ycenter aste-earfrequency of coil is higher land 'is tuned by 'capacitor 21, toward `the frequency range Aof `coil 14, the resultant angle of slope 48, representing @the high frequency side of the response curve A becomes steeper with limited correcting factor of the video intelligence, upto a certain point. This adjustment ,also limits side band ringing While slightly reducingthe 'band pass frequency range of the two coils 14 and 30, as represented by response curve band width 50. This makes it possible to improve picture det-ail and resolution by placing the picture carrier at the base of the resultant response curve slope, -for example, at 457.75 rnc. point and choosing and adjusting the angle of the slope by the action of coil 2l)v on coil 1'4, and action of coil 50 on coil 1-4 for phase correction in a more complete control.

For example, when the coils 14 and 30, in conjunction with their capacitors 13 and 33, respectively, are properly adjusted to the same frequency range, a maximum 4band width with clearer picture information and detail are obtained; each respective coil and capacitor 13, 14 and 39, 33, act as one coil to tune the whole curve on "both sides or both the high andlow frequency sides, and with the slope 48 has a frequency range of about .75 megacycle from the top of the curve A -to the beginning of the point Si), which is the picture carrier side of the response curve A. Thus, it will be recognized that i-n the connected coil and transmission line arrangement, as `herein described, .thejpicture carrier positionis near the baseline of the resultant response curve, the slope of which'is controlled-bythe Iaction of coil 20 and capacitor 21 tuned so its center frequency is higher in frequency vand near the frequency range o'f coil 14 and capacitor 13. both sides of the response curve, for phase correction, coil 30 tunes both sides 'of the response curve land coil 14, in conjunction with coil 20 .tunes vthe slope of the picture carrier side of the response cur-ve. With coil 14 and coil 30 tuning both `sides of the response curve, the band width can be controlled by positioning of the respective taps 26 and 29, separately or together, toward the middle of each or both of their relative coils for greater band pass. .The effect of utilizing the' taps 26 and Z9 near the base ofthe coils, adjacent the core inserts 19 and 46, has the 'equivalent propertyv of moving lthe `taps nearer the 'middle of the coils, as described, increases the frequency range and makes the band pass wider with frequency range v'between slopes of relative 'equal -amplitude and all frequencies in the 'band pass,

as -illustrated in the resultant response .curve graph. Alternately, 'as indicated, the one ,or both iron cores 19 and 46 will var'y the inductive value between rela-tive points T2 and Tg1, by variable adjustment in their relative coils 14 and 31), respectively. Thereby, the band pass filter allows the use vvof a one stage for the picture strip with control of the band width lwhile regulating the picture .carriers side bands to `produce a correction of `the `phase ofthe rectied side bands.

Through control of the degree of slope, as described, and the frequency fra-nge .of the coils and transmission line, some novel 'characteristics of the resultant response curve are produced. -For example, 'one property of the bandH pass ifilter 'is *obtained Ibytuning coil 14 `to "one In this relationship, 'the coil 1:4 tunes.

frequency, for example '45 'megaclyc'lea and -tuning coil 3'0 to an adjacent frequency, for example, 40 megacycles, obtaining a band width, as `represented by the resultant response which will Ybe all frequencies therebetween, with'a flat response of these inbetween frequencies and with band width on theqorder of `6 mc. or so but kWith less amplitude. However, thevphase correction property of clearer video intelligence will be lost rif either coil willjnot individually tune frequency movement on both sides of the response curve in the output stage so arranged. Having the Yinductive values at the low impedanee `ends of the coils with the feature or inductance across` the transmission line being in 'phase with the resonant circuits Vand 'all parts of the same inductance no lag or lead Y is present.. With the in-phaseinductance value at'the transmission tap near the base of the coils, as described, an increased `and greater 'phase correction is present 'when vthe coils lei-"and 30` are tuned to the same frequency and produce relative frequency movement toward the low frequency side or the high frequency side of the band `pass `response curve. `In vvery sensitive picture tube structure, phase correction is obtained Without peaking coils and -video amplifiers, utilized after the transmission of intelligence through the strip :and can be eliminated.Y

When the band pass lter is mistuned,it has the property of reflecting an image much like `.that of a mirror resultant response curve.

and another response curve Br adjacent in 'frequency 'to the main response curve A is obtained. The image curve B .has the same shape as the response curve A but is of much less amplitude. -For example, in the 'relative tuning of the coils 14 and 30, the coil 1'4, with coil'20 is a tuned circuit, yas indicated, wherein center 'frequency controlled by coil 20 'is higher yin vfrequency and adjusted towards the 4frequency range of coil 14 to form and steepen the slope of the high vfrequency side of the In addition, when coils 14 and 30 are vtuned to adjacent frequencies a maximum band width is obtained, the coils do not track and there is no phase correction. However, a wide band pass of 6 to 8 mc. may be produced by tuning coils y1'4 and '30 Ito adjacent frequencies with a flat response curve, for example. Control of band pass width with phase correction, 'can be used in vcolor Vequipment in a two stage strip to obtain gain, in `the'place of other structure 'now used as in 5 stage picture strip lfor color.

In tuning the frequency of coil 20 toward the frequency of coil 14, `which .obtains a reduction of band pass frequency and proper slope of the high frequency side of the response curve, the'coil 20 can be mistuned to have the image B, of the response curve A, if any energyis hunched past the 45.75 towards the 46 megacycle point of the response curve. This image B of the response curve is at reduced amplitude adjacent to the frequency range of the band Vpass and indicates that the coil 20, with capacitor 21, center frequency is tuned too close to the saine frequency of capacitor 13 and coil 14 and that there is, in effect, an overshot of the whole band j pass curve, the overshot being atless amplitude than the vresponse curveas indicated by prime markings on B and is the result of mistuning the band pass. Thus, while the tuning effects of coil 14 and coil 30- bothhave an effect upon the picture carrier side bands, as Well as the frequency range of the band "pass lter, -it will be recognized that improved picture detail is obtained by combining therewith a control of the V'slope characteristics of the band pass. Funther, coil 30 can be unbalanced to produce the eects of ringing at load resistor 37, as a 4total effect, even if the response curve is satisfactorily obtained. This ringing appears to be produced by magnetically or electrostatically coupling a resonant .circuit thereinto.

From the above description, it will be recognized that this arrangement of aband pass filter, properly 'tuned as a reflector and not a trap absorption arrangement, eliminates Ythe necessity of shielding the output circuit and makes it possible to use a one-stage output picture strip with high eiiiciency high gain, adequate band width, adequate slope angle adjustment, and phase correction. By the above indicated control of band width and angle of slope adjustment on the picture carrier side of the response curve, there is illustrated the relative'control of frequency range and both sides of the resultant re sponse curve in a one stage output picture strip to reproduce picture information with improved detail and reso-V lotion. The band pass filter arrangement and its method can be employed wherever wide band pass or sharp band pass is required and wherever a resonant band pass filter is employed or required, i.e. other than an I.-`F. picture strip, as with a transmitter amplifier, or as in an interstage coupling device.

By the above band pass filter arrangement, as described, it will be recognized that there is provided a method and structure wherein the reflected energy is addedV to the energy of the resonant circuit input tap coil, the high capacitive resonant circuit is tuned by insertion of an Yiron core and establishing a center frequency which when tuned nearer' to the frequency range of the band pass lters input and output tap coil, the angle of slope is increased in the'resultant response curve. In the arrangement of output stage the high capacitive reactive resonant circuit is tuned to operate on Vthe high frequency side of the resultant response curve thereby controlling the high frequency slope of the resultant response curve. The high capacitive reactance resonant circuit is inductively coupled at the high impedance end of the tap input coil of the band pass filter arrangement, and as the angle of slope is increased, the ringing of picture carrier side bands is balanced out or is damped out and is eliminated upon rectification of picture carriers side bands on obtaining video intelligence in an output stage of this arrangement. The high capacitive reactance coil circuit and the input tap coil circuit have their low impedance sides connected together. Thus in Vtieing the whole arrangement together it will be recognized that slope, width and phase correction is obtained in tuning the system as a reflector and not as an absorption trap. When mistuned the whole arrangement gives the effect of an absorption trap and is no longer a reflector.

In the arrangement of two tap coils tuned to coincide in frequency range with a transmission line connecting them together, the phase correcting factor is apparent to a great degree in the resultant video intelligence.

In the grid circuit arrangement which provides improved and more favorable intercarrier sound output with regard to amplitude of sound carrier to picture carrier, coupled with the band pass filter for picture control, -as illustrated, is a medium type LC grid circuit. This circuit produces a more favorable reduction in arnplitude of sound LF. carrier frequency to beat with the picture carrier at a 4.5 mc. intercarrier sound output through diode 17. yIn this arrangement the 6CB6 tube is coupled with a plate current limiting resistor 53 of 3900 ohm value; a .0015 mf. screen by-pass capacitor 54; an 18,000 ohm screen limiting resistor 58, a 330 ohm cathode bias resistor 56, and a .0015 mf. cathode by-pass condenser 57. The grid is grounded through an 18,000 ohm grid return resistance 59 and coupled through a 150 mmfd. capacitor 60 to conductor 6i. The conductor 6i is coupled to the high impedance side and to the low impedance side of signal input grid coil 62 through a 15 to 20 mmfd. noninductive (NPO) variable capacitor 63. rlfhe resonant circuits are provided with NPO ceramic capacitors.

The low impedance side of coil 62 is connected by conductor 64 to the low impedance side of a resonant coil 65 which in turn is connected across its high impedance side and low impedance side by a relatively high capaci-V tive capacitor 66 of 79 mmfd. The coil 62, for example,

is a space Wound coil 1A inch in diameter of number 21 conductor wire with 26 threads tothe inch. Coil 65, for example, is a space wound coil 1A inch in diameter space wound of Number 27 conductor wire of 4.25 turns, with 26 threads to the inch. The spacing between the relative high impedance ends of coils 62 and 65 is 1/16 inch to 1/s inch. This coil spacing controls the sound carrier ratio to picture carrier for more favorable sound output.

The signal input grid coil 62 is tuned by variable capaciter 63 to admit a large band pass in conjunction with resistor 59 and is provided with the adjustable iron core 70 for tuning to the frequency range of the response curve. The coil 65 is provided with an adjustable iron tuning core 71. The action of the coil 65, tuning core 71 and capacitor 66 relative to coil 62 and capacitor 63 is similar to the action of coil 20, core 25 and capacitor 21 upon coil 14 and capacitor 13. The coil 65 reflects energy back to coil 62 increasing its amplitude and sharpening the slope of the resultant response curve rat the low frequency side of the resultant response curve, as represented by the dotted line shown in the graph 'n1 Figure 2. In other words, the coil 65 with condenser 66 resonates near frequency range of sound channel I.F. for the rejection of sound interference in picture display and for a more favorable reduction in amplitude of sound I.F. carrier frequency to beat with the picture carrier frequency to produce the 4.5 mc. in-V tercarrier sound output, and is positioned at 41.25 mc. point on the dotted lines in the graph. Thus, with an arrangement and method, as described, it has been found that improved intercarrier sound output is obtained as a result of mixing LF. sound carrier and I.F. picture carrier in the combined reiiector systems, as described.

In further explanation of the structure, as above described, there is provided a frequency range band pass resonant filter consisting of a resonant input tap coil with a high capacitive reactance resonant coil inductivcly coupled electromagnetically and electrostatically to the high impedance end of the input coil. One end of a low impedance coaxial transmission line is connected to the tap portion and to the low impedance end of the input coil, and the other end of the transmission line is connected to the tap portion and to the low impedance end of the lout-put coil. The inductive magntude across the tap portion of both input coil and output coil, at the low impedance ends of the two coils, controls the band pass frequency range and the band pass amplitude range of a band pass resonant lter, as illustrated by the resultant response curve thereof. In operation, the high capacitive reactance resonant coil center frequency is tuned to an adjacent higher frequency range than the band pass lter frequency range of the input resonant coil transmission line output coil in which the input tap coil circuit and the output tap coil circuit coincide in frequency range to produce a resultant response curve which displays a Vsteep slope on both sides of its frequency range of the band pass filter in which the amplitude of all frequencies between the slopes are of `equal or substantially equal height. That is, when each coil individually produces movement of frequency range of the resultant response curve; when a picture carrier and its side bands are inserted at the high frequency side of response curve and picture carrier is placed near .to the base line of the resultant response curve of the band pass frequency range filter arrangement, and when energy of the picture carrier side bands lis reflected 4from the high capacitive reactance resonant coil circuit to the input coil transmission line output coil band pass frequency range circuitand is included in the output of energy from the band pass filter circuit there Iis accomplished the control of the angle of slope of the high frequency side off the resultant response curve, the ringing factor, the phase correcting factor, contrast range factor increasing range of black and White fana-'asas picture contrast, and the production of clearer picture detail in the picture display.

`Further, the -hig'h 'capacitive reactance resonant coi circuit when tuned to an adjacent highei center frequency range Ythan the band pass frequency lrange of the input resonant coil,ltransn1is'si`on -line land `output coil, Ithen the high capacitive resonant coil 'circuit produces the effect of steepening Aand controlling 'the 'angle of slope of 4a resultant response lcurveY in which the input coil circuit and the output 'coil circuit areltuned to fadjae cent frequency ranges and the inductive magnitude across the ends of the transmission line fc'o'n'trols the mum frequency rangeof th'e lresultant responseA 4curve f and input coil circuit and outputcoil circuit -controlfthe maximum Afrequency range of -if'resultant response curve.

EIn v'the combination there isprv'id'eda grid coil arrangement of an output stage fof afbandpass ilterfin which the grid coil resonant circuit lcalpaeit'zr value, fin conjunction with resistor 59, 'is 'chosen to admit the same frequency range as a band pass filter frequency range. The grid circuit is an arrangement inV which (a high capaci-tive resonant circuit'is 'inductivelyecoupled "electro-magnetically and electrostatically `vto the ygridV circuit. kiIt's center frequ-ency is ltuned lower iin frequenc'yirange 'than the grid coil circuit' and lis inductive'ly @coupled t'o the high im'- pedanceside vof the 2giid oo'il vcircuit lin 'which A'the idegree of coupling of these two 2coils control the balance [and amplitude =of sound car-fier to *picture Acarrier energy for obtaining va beat frequency output yfor s'ou'nd 'intelligence in 'the plate circuit lby a ldiode rriixer, Y"energy is rcile'cte'd to lthe grid Sc'oil "circuit lfrom ythehi'gh capacitive resonant coilfcir'cuit and .'i's added lto it upon insertion of picture carrier and Iside Jbands fand sound Xcarrier inputs to thegrid coil e. coucher-eef. i l 'Inaccordance with Ithefpatentfstatutes, ITliave described the principles 'of constmctlion and operation fof 5my band .pass filter fand method of improving 'picture detail #with sound output, and while i lhave endeavored lto yset forth the best 1eineociirn'eiit thereof, desire :te have it under- Y stood fthat changes may be inade Within 'the 'scopeof "the following claims without Edeparting from the spirit cf my invention and improvement.

Ifc'laim:

, AIn the control of lt-h'e range -of amplitude of -modulated .components Vand-Irai'ige of-amplitude of carrier in the separation of carrier 'land modulated 'components to control Sand increase lthe amplitude of Lthe dernodulated Vcomponents :from said f'ca'rrier in their related `afmplituc'le relationship, fa structure consisting #of ian -ing'mt tapped turn inductor andan output tapped v-tui-'n inductor with Yshunt condensers for each said 'induotoig said tappedturnlinductors being connected and coupledbyatransmission line at theftapped turn point andthe beginning of tur-n -offeach inductor, with k.the :input tapped tur-n 'induotor inductively coupled toa ipa-rallel "inductorisliuntlcondenser circuit, and a parallel shunt condenserinductor, means {fo'r inserting a carrier witlizxnodulated components, means 4for detecting modulated components, teach tapped tur-n inductor tuned to produce simultaneously Aaslight frequency movement of Lthe fsaid structure frequency Vresponse range to 'establish a characteristic frequency range of .said structure thereby keeping Ithe'modulated components of zsaid carrier in phase relationship, having thefrequency range Aoffsaid v change when derno'dulatedand said demodul-a'ted :come pcnents 1wr1'1 4have greater amplitude with no phase shift of said modulated 4components from said carrier. i

2. In la band pass lter system for controlling 4:band pass 'frequency-range with no phase shift 'of modulated intelligence, the "structure tm'mprising in combination an input Jsignal'source, "a tapped turn input coil having a -low 'impedance ibeginning point co'nnected to said signal source, aA tapped turn 4point near said low impedance and 'beginning point, "and "a high impedance end point counected'to saidisignal source, a'tapped turn output coil having a corresponding low impedance beginning point, 'a 'tappedtuin point and an vend point in uncoupled field relationship relative t'o said input co'il, a lowimpedance transmission line coupling/said input v'coil and said output coil at the said low impedance Ibeginning and tapped turn "points thereof, and resonance controlling shunt capacitors connected across the beginning and the end of each of said input-coil "and said out-putco'i'l, whereby Vwhen a frequency-response curve is obtained "therefrom, the band width frequency is :controlled by the ,magnitude of turns Yratio Abetween the said low impedance beginning points and said tapped tum points for a controlof ythe inductive value 'across 'each end of said "transmission 'line and 'each of |the 'said coils simultaneously :control the said 'band pass frequency ranges. I

3, Y The structure of zclaim 2 including fin the input coil circuit a tuning coilinductively coupled to said input coil circuit for controlling 4the frequency lrange of the band pass iiltrer without absorbing energy'of 'the band pass frequency range. v

2l. The 'structure of claim 2 wherein said input signal source is an amplifier "having auoutput -plate circuit and an input grid circuit, said input grid vcircuit comprising a control grid circuit 'including a `grid coil having 'a high impedance end and a Ylow impedance end, a grid coil shunt condenser, Ya series capacitor, vand a .grid return resistance connecting said grid to vvground, and y`apa1alle'l resonant circuit inductively lcoupled Vto the 'high 'impedlance end Aof the said Vgrid coil, and saidg'rid coil circuit and -said parallel resonant circuit having `their low impedance ends connected together `and to' ground, whereby in producing a resultant response curve therefrom the combination is tuned to ysteepen the frequency range of the resultant response curve and vincrease the amplitude of a resultant response curve in which the `said .parallel resonant :circuit will 'not absorb the slope range of frequencies i'n the resultant response curve.

5. ln combination, 'with aftelevision receiver system for mixing carriers 'of'p'icture I.F. carrier and sound `I.F. carrier Avto produce intercarrier sound with elimination of sound interference vin a television display, va structure comprising a high frequency system including an input signal source, an input coil having a 'low impedance beginning point connected 'to said signal source, ka tapped turn point Inear said low impedance beginning point and a high impedance end point connected to said rsignal source, a resonance controllingshunt capacitor ,connected across the -said 'beginning 'and Aend of said 'input coil, (an output coil lhaving a corresponding :low impedance beginning point, a tapped turn point vand an .end point, a resonance V`controlling shunt capacitor connected across the said beginning and end points of said output coil, a Slow impedance transmission line coupling said input coil at thesaid tapped turn ypoints thereof and said outputcoil, an insulating blocking coupling capacitor in said transmission line, a video yrectifier and output circuit connected Ito said ouput coil, said input signal source comprising a vacuum tube system including a plate element and circuit connected to said Vinput coil, and ;avacuum tube amplifier including agrid Vcircuit v'having/a rgrid coil shunt condenser inductively coupled to anothergrid coil shunt condenser. i

Y 6. in a single'stage band pass filter 'system for tuning and preventing phase shift of transmitted carrier side bands with high Q of the coils substantially undisturbed, the structure comprising a signal source, a tapped turn input co'il and circuit of variable inductance, with said coil having a high impedance end and a W impedance end connected to said signal source, a resonance shunt controlling capacitor across said input coil connected directly to the high impedance end and low impedance ends thereof, a tapped turn output coil and circuit of variable inductance with said coil magnetically shielded from said input co'il and having a high impedance end and a low impedance end, a resonance shunt controlling capacitor across said output coil and connected directly to the high impedance end and 10W impedance ends thereof, and a low impedance coaxial transmission line and blocking condenser connecting said input coil at tapped turn points thereon and said output coil at tapped turn points thereon with said shunt capacitors determining the degree of coupling of the said tapped turn coils.

7. ln a television receiver system of the intercarrier type having an intermediate frequency amplifier channel including a plurality of cascade connecting amplifier stages, means for impressing a television signal on the linput of said channel, a picture carrier and a sound carrier, means for detecting the beat frequency of the difference in frequency between said picture carrier and said sound carrier, said intermediate frequency channel having an out-put stage including an o'utput plate circuit and input grid circuit for said stage, the said plate circuit including two electrostatically and magnetically shielded tapped turn inductors each with high impedance ends and low impedance ends and each connected across their ends respectively with resonance controlling shunt condensers, a low impedance transmission line connecting and coupling the two tapped turn inductors at tapped turn points at the said low impedance ends o'f each inductor, with said resonance shunt condensers controlling the degree of coupling of said tapped turn coils, and the said grid circuit of the said output stage including a grid connected to a resistor to ground and through a capacitor to' a grid coil resonant circuit shunted inductor coil and an inductively coupled condenser shunted inductor coil inductively coupled to said grid coil resonant circuit.

8. In a band pass control structure for transmission of high frequency carrier waves from an input circuit, a band pass filter to an output circuit comprising an input circuit and an output circuit, a circuit o'f two tapped turn inductors having relative high impedance ends and low impedance ends, variable shunt-capacitors independently connected directly across each of said inductors respective ends and a low impedance transmission line which connects and couples a portion of the two inductors together at their relative low impedance ends and each inductor will simultaneously tune both slopes of resultant frequency range to a characteristic frequency band range having carrier high frequency side bands and low frequency side bands and wherein the frequency response range will produce no phase shift of high frequency carrier side bands and low frequency carrier side bands.

9. In a band pass lter system for control of the frequency response range of signal source, the structure consisting of two tapped turn resonant inductors with resonance controlling shunt capacitors therefor and a transmission line in which the transmission line connects and couples the two resonant inductors with the said resonance shunt capacitors being `independently connected at the beginning point of each resonant tapped turn coil and the end point of each tapped turn coil, whereby when the aforementioned structure is tuned to a frequency range to obtain simultaneously by each inductor a slight frequency movement at the low frequency side of slope and at the high frequency side of slope of the resultant frequency response curve, the characteristic frequency response range of the said structure is directly proportional to the increase in the inductive value at the aforementioned portion of each inductor for the same range of frequency. Y.

l0. In the control of the mutual coupling of two shunt condenser tapped turn inductors `in a band pass frequency structure connected to a signal source, the arrangement consisting of two tap turn inductors with resonancecontrolling shunt condensers having capacity reactance independently connected directly across' each inductor and a transmission line, in which the transmission line ,connects and inductively couples the two tapped turn inductors in isolated relationship at a portion of each inductors tap turnfand beginning of turn of each inductor, whereby when the arrangement is tuned to a frequency range in which each inductor will simultaneously produce a slight frequency movement at the low frequency side of slope and at the high frequency side of slope of the resultant frequency response curve, the magnitude of coupling of the two connected inductors is directly proportional to the increase in the capacity reactance value of the said inductors shunt condensers at the same range of frequencies.

1l. In a television receiver system of the type having an intermediate frequency amplifier channel including a plurality of cascade connecting amplifier stages, means for impressing a television signal on the input of said channel including a picture carrier having modulated components and a sound intermediate frequency carrier, means for detecting the modulated components and an output amplifier stage in said intermediate frequency channel in which the output amplifier stage consists of a plate output circuit and a grid input circuit in which the said output plate circuit consists of two tapped turn inductors with resonance controlling shunt capacitors independently connected across the said high and low ends respectively of each inductor and a transmission line in which the transmission line connects and couples the two tapped turn inductors at a tapped turn point at the beginning of a turn of each inductor, and when the said plate circuit is tuned to a frequency range in which each inductor will simultaneously produce a slight frequency movement on both slopes of a resultant frequency response curve of the said plate circuit, the input grid circuit of the said output amplifier stage consists of a grid connected to a resistor and through a condenser to a gridY shunt inductor having a condenser shunted inductor inductively coupled to said grid inductor in which the coupled condenser shunted iniductors frequency range is tuned to attenuate the sound intermediate frequency carrier of the channel amplier and the grid shunt inductors frequency range is tuned toward an adjacent frequency range of the output plate circuit of said output amplifier resultant frequency response range until intermediate beat frequency and mixer in plate circuit cut 0E in plate circuit at I.F. sound frequency and the resultant plate circuit response curve frequency range indicates the frequency range controlled by the said condenser shunted inductor appears to reflect energy of the response curve back to theV grid shunt inductors frequency control part of said resultant response curve increasing the amplitude of the slope of the frequency range the grid circuit controls, whereby when this effect is accomplished all of said modulated components of the picture carrier in the frequency range of the overall frequency response curve will have no phase shift and the linear length of the transmission line affects the detected modulated components and controls the leading edge and trailing edge of the demodulated components of the picture carrier.

l2. In a television receiver system of the intercarrier type having an intermediate frequency amplifier channel including a plurality of cascade connecting amplifier stages means for impressing a television signal on the input of said channel, including a picture carrier and a sound carrier with means for detecting the beat frequency of the dilerence `in frequency between picture carrier and sound carrier, said intermediate frequency channel having 13 an output stage with an output plate circuit and an input grid circuit for said stage, in which the said plate circuit consists of two tapped turn coil inductors with high impedance ends and low impedance ends and resonance controlling shunt condensers across each inductor and a transmission line, in which the transmission line connects and couples the two tap turn inductors in isolated relationship at tapped turn points near the beginning of turn of each inductor coil, and the said plate circuit is tuned to a frequency range in which each inductor will simultaneously produce a slight frequency movement on both sides-of the resultant frequency response curve of the said plate circuit; the input grid circuit of the said output stage consists of a grid connected resistor and shunt inductor and an inductively coupled condenser shunt inductor coupling in relation to the said grid resistor and shunt inductor of the said grid circuit ofthe output stage, whereby the degree of attenuation of the intermediate f requency sound carrier is controlled.

13. In the conn-ol of the characteristic frequency range of `a band pass lter system, the structure consisting of two tapped turn resonant inductors with resonance controlling shunt condensers connected across said inductors and a low impedance transmission line `and series coupling condenser in which the transmission line connects and inductively couples the said tapped turn inductors at Y tapped turn points near the beginning of turn of each inductor, in which, when the two tapped turn inductors, shunt oondensers `and the transmission line are tuned to a frevquency range wherein each inductor will simultaneously produce 'a slight frequency movement on both sides of the resultant frequency response curve, the characteristic frequency range of the aforementioned structure will have a relatively small range of frequency in the slope-portion of the response curve and the resultant frequency response range will be the only frequency response with all other adjacent frequencies cut oi and all frequencies in h between the slope range of frequency will be of relatively equal amplitude upon the proper capacity value of the said resonant capacitors.-v

References Cited in the ille of this patent UNITED STATES PATENTS 

